1. Field of the Invention
This invention relates to an apparatus for determining a media feature, comprising: a plurality of light filters such that the filters include a media measurement aperture and a calibration aperture and wherein the filters are spaced a predetermined distance apart to allow media to be introduced between the filters; a light source located substantially adjacent to one of the filters; and a light detector located substantially adjacent to another of the filters.
2. Description of the Related Art
Prior to the present invention, as set forth in general terms above and more specifically below, it is known, that image forming devices are capable of printing images on media sheets of varying widths. Printing beyond the edges of a media sheet can cause a number of problems. It wastes imaging material such as ink and/or toner. The wasted imaging material can damage or decrease the life span of the image forming device. Also, the wasted imaging material can be inadvertently transferred to another media sheet thereby degrading print quality.
It is also known, that sensors can be employed to detect a variety of media and media defects. Such sensors include sensors attached to moving carriages that scan across the media and fixed/stationary sensors. While these sensors are capable of detecting a variety of media and media defects, these sensors either require time to move which results in coordination complexity and loss of throughput (time lost while moving the sensor) or relatively small sensors that are expensive and may not provide enough resolution. Finally, none of these sensors detect media features, such as tabs and are self-calibrating.
It is apparent from the above that there exists a need in the art for a media sensing device which is capable of detecting media, media defects, and media features, such as tabs, but which at the same time is self-calibrating. It is a purpose of this invention to fulfill this and other needs in the art in a manner more apparent to the skilled artisan once given the following disclosure.